Golf club head

ABSTRACT

A golf club head comprises a basal body having a metallic surface, and a multilayer coating on the metallic surface, wherein the multilayer coating comprises a clear first layer on the metallic surface and a colored clear second layer on the clear first layer, and the basal body is visible through the multilayer coating. Preferably, the basal body has a mirror finish surface, satin finish surface, orange peel finish surface or the like under the multilayer coating. The multilayer coating further comprises an iridescent layer on the colored clear layer, wherein the iridescent layer includes iridescent material which is dispersed therein maintaining a certain degree of transparence.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a golf club head moreparticularly to a multilayer coat capable of improving the appearance.

[0002] In the golf club heads, there are demands for beauty andhigh-quality impression in the appearance as well as demands forperformance such as carry, directional controllability and like.

[0003] In recent years, on the other hand, there is a tendency for thewood-type golf clubs to increase the size or volume of the club head.

[0004] Sometimes, such a large volume head is felt to be heavy by thegolf player although the actual golf club is not heavy, and thisimpression different from the actual condition tends to affect golf playwhich requires concentration.

[0005] A principal factor in such a heavy impression is the appearance,namely, its coating, and it was discovered that a heavy impression canbe wiped away by improving the coating.

SUMMARY OF THE INVENTION

[0006] It is therefore, an object of the present invention to provide agolf club head in which a heavy impression of a large volume golf clubhead can be wiped away and also it will be appreciated by many golfersas being beautiful and high-quality.

[0007] According to the present invention, a golf club head comprises abasal body having a metallic surface, and a multilayer coating on themetallic surface, wherein the multilayer coating comprises a clear firstlayer on the metallic surface and a colored clear second layer on theclear first layer, and the basal body is visible through the multilayercoating.

[0008] Preferably, the basal body has a mirror finish surface, satinfinish surface, orange peel finish surface or the like under themultilayer coating. The multilayer coating further comprises aniridescent layer on the colored clear layer, wherein the iridescentlayer includes iridescent material which is dispersed thereinmaintaining a certain degree of transparence.

[0009] Therefore, it becomes possible to give a light impression to theuser.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a perspective view of a wood-type golf club headaccording to the present invention.

[0011]FIG. 2 is a cross sectional view of the multilayer coatingthereof.

[0012]FIG. 3 is a cross sectional view of another example of themultilayer coating.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] An embodiment of the present invention will now be described indetail in conjunction with the accompanying drawings.

[0014] In this embodiment, golf club head 1 according to the presentinvention is a wood-type golf head comprising a metallic basal body, thesurface of which excepting the sole is covered with a multilayer coating3. Incidentally, the coating area can be determined according to theneed.

[0015] The basal body 2 is made by assembling a plurality of parts madeby casting, forging, pressing and the like of at least one kind ofmetallic material. In this embodiment, a titanium alloy is used in theparts because the strength-to-weight ratio is high. But, it is alsopossible to use other materials.

[0016] Needless to say, a pattern or design can be provided on thesurface by various methods such as pressing, etching, cutting, filingand the like.

[0017] If need be, preparation of the surface of the basal body 2, e.g.polishing, wire brushing, sand blasting, cleaning and the like, is madein advance, and the surface to be coated is properly finished. As to thesurface finish, for example, bright finish (or mirror finish),semibright finish, dull finish, satin finish (inclusive of hair linefinish and matte finish), fine matte finish, orange peel finish and thelike may be made on the surface. If the surface has a pinhole or thelike, it should be stopped up with putty or the like in advance.

[0018] According to the invention, a clear paint is firstly applied tothe metallic surface of the basal body 2 to make a transparent colorlessfirst layer 3 a.

[0019] The clear paint is a transparent and colorless heat-hardeningpaint which contains a solvent and a synthetic resin such as polyester,epoxy, acrylic resin and the like as its base. In this embodiment, apolyester resin enamel is used because of a high impact strength andstrong adhesion to metallic materials such as titanium alloy, stainlessand the like.

[0020] In order to harden, the applied clear paint is baked, for exampleat about 150 deg. C. for about 15 to 20 minutes, whereby a hardtransparent colorless first layer 3 a is formed.

[0021] The first layer 3 a can also improve the adhesion to theunder-mentioned overcoat.

[0022] The first layer 3 a preferably has a thickness in a range of from5 to 40 microns, more preferably 10 to 25 microns.

[0023] If the thickness is less than 5 microns, it is difficult to eventhe microscopic roughness of the metallic surface. If more than 40microns, there is a tendency for the adhesion and impact resistance todecrease.

[0024] Secondly, a transparent color paint is applied to the surface ofthe transparent colorless first layer 3 a to make a colored clear secondlayer 3 b.

[0025] The transparent color paint is a transparent and coloredheat-hardening paint which contains a solvent, a synthetic resin such aspolyester, epoxy, acrylic resin and the like as its base, and colorant.As the colorant, dyestuff such as synthetic dye, vegetable dye, animaldye and mineral dye can be used alone or in combination. The dyestuffhas a particle diameter which is very small in comparison with pigment,for example 1 to 2 nanometers, therefore, the paint is renderedtransparent. However, another colorant may be used as far as it canrender the paint transparent in effect.

[0026] In order to harden, the applied transparent color paint is baked,for example at about 150 deg. C. for about 15 to 20 minutes, whereby ahard colored clear second layer 3 b is formed on the first layer 3 a.

[0027] If the colored clear second layer 3 b is too thin, it isdifficult for the user to obtain the undermentioned depth perception. Iftoo thick, the second layer 3 b becomes brittle.

[0028] Therefore, it is preferable that the thickness of the coloredclear second layer 3 b is set in a range of from 10 to 50 microns, morepreferably 20 to 40 microns.

[0029] In this embodiment, further, an iridescent third layer 3 c isformed on the colored clear second layer 3 b by applying an iridescentpaint.

[0030] The iridescent paint is a liquid heat-hardening paint whichcontains a solvent, a transparent colorless synthetic resin such aspolyester, polyurethane, epoxy, acrylic resin and the like as its base,and an iridescent material 4. A colorant such as pigment and dyestuff isnot used in this embodiment.

[0031] As to the iridescent material 4, colored specular aluminumflakes, specular metal flakes whose surface is resin-treated, micaflakes coated with a titanium oxide, flakes of mica itself can be used.Here, the colored aluminum flakes means aluminum flakes colored by vapordeposition. It is not always necessary that the iridescent materialitself is iridescent as far as the coating layer as a whole isiridescent. In case of material itself being iridescent, a chromaticpolarizing material can be used. Anyway, the average size of the flakeis set in a range of from about 10 to about 100 microns, wherein thesize of a flake is defined as a maximum size in the normal direction tothe thickness direction of the flake.

[0032] In this embodiment, an acrylic resin is used as the base resin,and colored aluminum flakes are used as the iridescent material. Thecolored aluminum flakes are preferable because it is easy to select acolor and obtain the same color and a higher reflectance in comparisonwith other materials.

[0033] In order to harden, the applied iridescent paint is baked, forexample at about 150 deg. C. for about 10 to 20 minutes, whereby a hardtransparent iridescent third layer 3 c is formed on the colored clearsecond layer 3 b.

[0034] If the iridescent third layer 3 c is too thin, the iridescenteffect can not be obtained. If too thick, the third layer 3 c becomesbrittle and the impact resistance decreases.

[0035] Therefore, the thickness of the iridescent third layer 3 c is setin a range of from 10 to 40 microns, preferably 15 to 35 microns. If theiridescent paint contains the iridescent material 4 too much, theiridescent material 4 covers the surface of the basal body 2 and it isdifficult to obtain the depth perception. If too less, it becomesdifficult to obtain the iridescent effect. Therefore, the iridescentmaterial 4 is set in a range of from 0.1 to 7.5%, preferably 0.5 to 5.5%in weight with respect to the total weight of the iridescent materialand the base resin (excluding solvent).

[0036] The flakes 4 of the iridescent material may be dispersed randomly(not oriented), but it is preferable to orient in a specific direction.

[0037] The flakes 4 can be oriented such that the flakes becomesgenerally in parallel with the surface of the coating as shown in FIG.2. This orientation may be preferably employed when the material itselfis iridescent such as a chromatic polarizing material. In this case, inorder to enhance the iridescent effect, relatively large flakes arepreferably used as far as the flakes do not to hide the surface of thebasal body.

[0038] Further, as shown in FIG. 3, the flakes 4 can be oriented suchthat the flakes becomes generally normal to the surface of the coating,in other words, the thickness directions of the flakes become generallyin parallel with the surface of the coating. In this case, when thecoating is viewed oppositely or normally thereto, the color is mainlydetermined by those of the second layer 3 b and the surface of the basalbody, but when viewed obliquely, as the percentage of the color of theiridescent material increases, the color as a whole changes. Thisorientation may be preferably employed when the material itself is notiridescent.

[0039] In any case, a color change also occurs by change in the incidentlight (direction and intensity) in addition to the change in thedirection of view. Incidentally, the former orientation can be achievedby brush application of the iridescent paint, dipping, spraying or thelike. The latter can be achieved by electrostatic spraying.

[0040] In this embodiment, furthermore, an outermost clear fourth layer3 d is formed on the iridescent third layer 3 c by applying a clearpaint in order to protect the iridescent third layer 3 c and enhance thedepth perception. It is however, possible to omit the outermost clearlayer 3 d, for example, if the third layer 3 c is relatively thick asshown in FIG. 3.

[0041] The clear paint is a transparent and colorless heat-hardeningpaint which contains a solvent, and a synthetic resin such as polyester,polyurethane, epoxy, acrylic resin and the like as its base.

[0042] The overall thickness (t) of the multilayer coating 3 is set in arange of not more than 100 microns, preferably 25 to 90 microns, morepreferably 40 to 80 microns in view of the impact resistance, durabilityand the like.

[0043] The multilayer coating 3 is transparent and does not containpigment, and the surface of the basal body 2 is visible through themultilayer coating 3. As a result, a depth perception occurs in humaneyes, and many of the users do not come to get a heavy impression of alarge volume head.

Comparison Tests

[0044] Using the basal body shown in FIG. 1 and described above,wood-type golf club heads were made, changing the specifications of themultilayer coating, and the appearance and impact resistance wereevaluated as follows. The results and the specifications are shown inTable 1.

[0045] Impact resistance test: A 500 gram iron bar was dropped to themultilayer coating from 150 mm height, and the multilayer coating wasinspected for damage, coming off and the depth of the dent and they werecomprehensively evaluated into five ranks as impact resistance, whereinthe larger the rank number, the better the impact resistance.

[0046] As to the appearance, with respect to the transparency, metallicsheen and high-quality impression, ten golfers evaluated the multilayercoating into five ranks. TABLE 1 Club head Ex. 1 Ex. 2 Ex. 3 Ref. 1 Ref.2 Ex. 4 Ex. 5 Basal body satin mirror shot shot shot satin satinFinishing method sanding polishing blasting blasting blasting sandingsanding Multilayer coating Thickness (micron) 1st first layer 15 15 1515  15 15  15 2nd colored clear layer 30 30 30 — — 5 55 2nd pigmentedlayer — — — 15  15 — — 3rd iridescent layer 20 20 20 — 20 20  20 4thclear layer 20 20 20 20  20 20  20 Test results Impact resistance  5  5 5 5  5 5  3 Appearance Transparency  5  5  5 1  2 3  5 Metallic sheen 5  5  3 1  1 5  4 High-quality impression  5  5  4 2  3 3  5

[0047] The present invention can be suitably applied to a wood-type golfclub head having a large volume in order to wipe away a heavy impressiontherefrom. However, as the present invention is effective in improvingthe appearance of the club head, it can be suitably applied toiron-type, utility-type and patter-type golf club heads as far as thesurface of the basal body is formed of a metallic material or thesurface is a metallic surface regardless of the actual material.

1. A golf club head comprising a basal body having a metallic surfaceand a multilayer coating on the metallic surface, wherein the multilayercoating comprises a clear first layer on the metallic surface and acolored clear second layer on the clear first layer, and the metallicsurface of the basal body is visible through the multilayer coating. 2.A golf club head according to claim 1, wherein the multilayer coatingcomprises said clear first layer, said colored clear second layer and aniridescent third layer on the colored clear second layer, the iridescentthird layer provided with iridescent material which is dispersed thereinmaintaining a certain degree of transparence of the iridescent thirdlayer.
 3. A golf club head according to claim 2, wherein the multilayercoating comprises said first, second and third layers and further anoutermost clear layer.
 4. A golf club head according to claim 1, 2 or 3,wherein the basal body has a mirror finish surface under the multilayercoating.
 5. A golf club head according to claim 1, 2 or 3, wherein thebasal body has a satin finish surface under the multilayer coating.
 6. Agolf club head according to claim 1, 2 or 3, wherein the basal body hasa orange peel finish surface under the multilayer coating.